From 22856f4af27a06d38935d4f373a46f3492a4bf08 Mon Sep 17 00:00:00 2001 From: Ahmad Peyvan <115842305+apey236@users.noreply.github.com> Date: Sun, 8 Oct 2023 03:22:36 -0400 Subject: [PATCH] Adding primitive variable Dirichlet BCs for Navier-Stokes parabolic terms for `P4estMesh{2}` (#1553) * Adding parabolic Dirichlet boundary condition example * add test * Correcting the format * Update src/equations/compressible_navier_stokes_2d.jl Co-authored-by: Jesse Chan <1156048+jlchan@users.noreply.github.com> * Update src/equations/compressible_navier_stokes_2d.jl Co-authored-by: Jesse Chan <1156048+jlchan@users.noreply.github.com> --------- Co-authored-by: Jesse Chan <1156048+jlchan@users.noreply.github.com> Co-authored-by: Hendrik Ranocha --- ...ir_navierstokes_convergence_nonperiodic.jl | 215 ++++++++++++++++++ .../compressible_navier_stokes_2d.jl | 29 +++ test/test_parabolic_2d.jl | 8 + 3 files changed, 252 insertions(+) create mode 100644 examples/p4est_2d_dgsem/elixir_navierstokes_convergence_nonperiodic.jl diff --git a/examples/p4est_2d_dgsem/elixir_navierstokes_convergence_nonperiodic.jl b/examples/p4est_2d_dgsem/elixir_navierstokes_convergence_nonperiodic.jl new file mode 100644 index 00000000000..935f132ba4b --- /dev/null +++ b/examples/p4est_2d_dgsem/elixir_navierstokes_convergence_nonperiodic.jl @@ -0,0 +1,215 @@ +using OrdinaryDiffEq +using Trixi + +############################################################################### +# semidiscretization of the ideal compressible Navier-Stokes equations + +prandtl_number() = 0.72 +mu() = 0.01 + +equations = CompressibleEulerEquations2D(1.4) +equations_parabolic = CompressibleNavierStokesDiffusion2D(equations, mu=mu(), Prandtl=prandtl_number(), + gradient_variables=GradientVariablesPrimitive()) + +# Create DG solver with polynomial degree = 3 and (local) Lax-Friedrichs/Rusanov flux as surface flux +solver = DGSEM(polydeg=3, surface_flux=flux_lax_friedrichs, + volume_integral=VolumeIntegralWeakForm()) + +coordinates_min = (-1.0, -1.0) # minimum coordinates (min(x), min(y)) +coordinates_max = ( 1.0, 1.0) # maximum coordinates (max(x), max(y)) + +trees_per_dimension = (4, 4) +mesh = P4estMesh(trees_per_dimension, + polydeg=3, initial_refinement_level=2, + coordinates_min=coordinates_min, coordinates_max=coordinates_max, + periodicity=(false, false)) + +# Note: the initial condition cannot be specialized to `CompressibleNavierStokesDiffusion2D` +# since it is called by both the parabolic solver (which passes in `CompressibleNavierStokesDiffusion2D`) +# and by the initial condition (which passes in `CompressibleEulerEquations2D`). +# This convergence test setup was originally derived by Andrew Winters (@andrewwinters5000) +function initial_condition_navier_stokes_convergence_test(x, t, equations) + # Amplitude and shift + A = 0.5 + c = 2.0 + + # convenience values for trig. functions + pi_x = pi * x[1] + pi_y = pi * x[2] + pi_t = pi * t + + rho = c + A * sin(pi_x) * cos(pi_y) * cos(pi_t) + v1 = sin(pi_x) * log(x[2] + 2.0) * (1.0 - exp(-A * (x[2] - 1.0)) ) * cos(pi_t) + v2 = v1 + p = rho^2 + + return prim2cons(SVector(rho, v1, v2, p), equations) +end + +@inline function source_terms_navier_stokes_convergence_test(u, x, t, equations) + y = x[2] + + # TODO: parabolic + # we currently need to hardcode these parameters until we fix the "combined equation" issue + # see also https://github.com/trixi-framework/Trixi.jl/pull/1160 + inv_gamma_minus_one = inv(equations.gamma - 1) + Pr = prandtl_number() + mu_ = mu() + + # Same settings as in `initial_condition` + # Amplitude and shift + A = 0.5 + c = 2.0 + + # convenience values for trig. functions + pi_x = pi * x[1] + pi_y = pi * x[2] + pi_t = pi * t + + # compute the manufactured solution and all necessary derivatives + rho = c + A * sin(pi_x) * cos(pi_y) * cos(pi_t) + rho_t = -pi * A * sin(pi_x) * cos(pi_y) * sin(pi_t) + rho_x = pi * A * cos(pi_x) * cos(pi_y) * cos(pi_t) + rho_y = -pi * A * sin(pi_x) * sin(pi_y) * cos(pi_t) + rho_xx = -pi * pi * A * sin(pi_x) * cos(pi_y) * cos(pi_t) + rho_yy = -pi * pi * A * sin(pi_x) * cos(pi_y) * cos(pi_t) + + v1 = sin(pi_x) * log(y + 2.0) * (1.0 - exp(-A * (y - 1.0))) * cos(pi_t) + v1_t = -pi * sin(pi_x) * log(y + 2.0) * (1.0 - exp(-A * (y - 1.0))) * sin(pi_t) + v1_x = pi * cos(pi_x) * log(y + 2.0) * (1.0 - exp(-A * (y - 1.0))) * cos(pi_t) + v1_y = sin(pi_x) * (A * log(y + 2.0) * exp(-A * (y - 1.0)) + (1.0 - exp(-A * (y - 1.0))) / (y + 2.0)) * cos(pi_t) + v1_xx = -pi * pi * sin(pi_x) * log(y + 2.0) * (1.0 - exp(-A * (y - 1.0))) * cos(pi_t) + v1_xy = pi * cos(pi_x) * (A * log(y + 2.0) * exp(-A * (y - 1.0)) + (1.0 - exp(-A * (y - 1.0))) / (y + 2.0)) * cos(pi_t) + v1_yy = (sin(pi_x) * ( 2.0 * A * exp(-A * (y - 1.0)) / (y + 2.0) + - A * A * log(y + 2.0) * exp(-A * (y - 1.0)) + - (1.0 - exp(-A * (y - 1.0))) / ((y + 2.0) * (y + 2.0))) * cos(pi_t)) + v2 = v1 + v2_t = v1_t + v2_x = v1_x + v2_y = v1_y + v2_xx = v1_xx + v2_xy = v1_xy + v2_yy = v1_yy + + p = rho * rho + p_t = 2.0 * rho * rho_t + p_x = 2.0 * rho * rho_x + p_y = 2.0 * rho * rho_y + p_xx = 2.0 * rho * rho_xx + 2.0 * rho_x * rho_x + p_yy = 2.0 * rho * rho_yy + 2.0 * rho_y * rho_y + + # Note this simplifies slightly because the ansatz assumes that v1 = v2 + E = p * inv_gamma_minus_one + 0.5 * rho * (v1^2 + v2^2) + E_t = p_t * inv_gamma_minus_one + rho_t * v1^2 + 2.0 * rho * v1 * v1_t + E_x = p_x * inv_gamma_minus_one + rho_x * v1^2 + 2.0 * rho * v1 * v1_x + E_y = p_y * inv_gamma_minus_one + rho_y * v1^2 + 2.0 * rho * v1 * v1_y + + # Some convenience constants + T_const = equations.gamma * inv_gamma_minus_one / Pr + inv_rho_cubed = 1.0 / (rho^3) + + # compute the source terms + # density equation + du1 = rho_t + rho_x * v1 + rho * v1_x + rho_y * v2 + rho * v2_y + + # x-momentum equation + du2 = ( rho_t * v1 + rho * v1_t + p_x + rho_x * v1^2 + + 2.0 * rho * v1 * v1_x + + rho_y * v1 * v2 + + rho * v1_y * v2 + + rho * v1 * v2_y + # stress tensor from x-direction + - 4.0 / 3.0 * v1_xx * mu_ + + 2.0 / 3.0 * v2_xy * mu_ + - v1_yy * mu_ + - v2_xy * mu_ ) + # y-momentum equation + du3 = ( rho_t * v2 + rho * v2_t + p_y + rho_x * v1 * v2 + + rho * v1_x * v2 + + rho * v1 * v2_x + + rho_y * v2^2 + + 2.0 * rho * v2 * v2_y + # stress tensor from y-direction + - v1_xy * mu_ + - v2_xx * mu_ + - 4.0 / 3.0 * v2_yy * mu_ + + 2.0 / 3.0 * v1_xy * mu_ ) + # total energy equation + du4 = ( E_t + v1_x * (E + p) + v1 * (E_x + p_x) + + v2_y * (E + p) + v2 * (E_y + p_y) + # stress tensor and temperature gradient terms from x-direction + - 4.0 / 3.0 * v1_xx * v1 * mu_ + + 2.0 / 3.0 * v2_xy * v1 * mu_ + - 4.0 / 3.0 * v1_x * v1_x * mu_ + + 2.0 / 3.0 * v2_y * v1_x * mu_ + - v1_xy * v2 * mu_ + - v2_xx * v2 * mu_ + - v1_y * v2_x * mu_ + - v2_x * v2_x * mu_ + - T_const * inv_rho_cubed * ( p_xx * rho * rho + - 2.0 * p_x * rho * rho_x + + 2.0 * p * rho_x * rho_x + - p * rho * rho_xx ) * mu_ + # stress tensor and temperature gradient terms from y-direction + - v1_yy * v1 * mu_ + - v2_xy * v1 * mu_ + - v1_y * v1_y * mu_ + - v2_x * v1_y * mu_ + - 4.0 / 3.0 * v2_yy * v2 * mu_ + + 2.0 / 3.0 * v1_xy * v2 * mu_ + - 4.0 / 3.0 * v2_y * v2_y * mu_ + + 2.0 / 3.0 * v1_x * v2_y * mu_ + - T_const * inv_rho_cubed * ( p_yy * rho * rho + - 2.0 * p_y * rho * rho_y + + 2.0 * p * rho_y * rho_y + - p * rho * rho_yy ) * mu_ ) + + return SVector(du1, du2, du3, du4) +end + +initial_condition = initial_condition_navier_stokes_convergence_test + +# BC types +velocity_bc_top_bottom = NoSlip((x, t, equations) -> initial_condition_navier_stokes_convergence_test(x, t, equations)[2:3]) +heat_bc_top_bottom = Adiabatic((x, t, equations) -> 0.0) +boundary_condition_top_bottom = BoundaryConditionNavierStokesWall(velocity_bc_top_bottom, heat_bc_top_bottom) + +boundary_condition_left_right = BoundaryConditionDirichlet(initial_condition_navier_stokes_convergence_test) + +# define inviscid boundary conditions +boundary_conditions = Dict(:x_neg => boundary_condition_left_right, + :x_pos => boundary_condition_left_right, + :y_neg => boundary_condition_slip_wall, + :y_pos => boundary_condition_slip_wall) + +# define viscous boundary conditions +boundary_conditions_parabolic = Dict(:x_neg => boundary_condition_left_right, + :x_pos => boundary_condition_left_right, + :y_neg => boundary_condition_top_bottom, + :y_pos => boundary_condition_top_bottom) + +semi = SemidiscretizationHyperbolicParabolic(mesh, (equations, equations_parabolic), initial_condition, solver; + boundary_conditions=(boundary_conditions, boundary_conditions_parabolic), + source_terms=source_terms_navier_stokes_convergence_test) + +# ############################################################################### +# # ODE solvers, callbacks etc. + +# Create ODE problem with time span `tspan` +tspan = (0.0, 0.5) +ode = semidiscretize(semi, tspan) + +summary_callback = SummaryCallback() +alive_callback = AliveCallback(alive_interval=10) +analysis_interval = 100 +analysis_callback = AnalysisCallback(semi, interval=analysis_interval) +callbacks = CallbackSet(summary_callback, alive_callback, analysis_callback) + +############################################################################### +# run the simulation + +time_int_tol = 1e-8 +sol = solve(ode, RDPK3SpFSAL49(); abstol=time_int_tol, reltol=time_int_tol, dt = 1e-5, + ode_default_options()..., callback=callbacks) +summary_callback() # print the timer summary + diff --git a/src/equations/compressible_navier_stokes_2d.jl b/src/equations/compressible_navier_stokes_2d.jl index b10ffa3b9d3..80857999017 100644 --- a/src/equations/compressible_navier_stokes_2d.jl +++ b/src/equations/compressible_navier_stokes_2d.jl @@ -456,4 +456,33 @@ end }) return SVector(flux_inner[1], flux_inner[2], flux_inner[3], flux_inner[4]) end + +# Dirichlet Boundary Condition for P4est mesh + +@inline function (boundary_condition::BoundaryConditionDirichlet)(flux_inner, + u_inner, + normal::AbstractVector, + x, t, + operator_type::Gradient, + equations::CompressibleNavierStokesDiffusion2D{ + GradientVariablesPrimitive + }) + # BCs are usually specified as conservative variables so we convert them to primitive variables + # because the gradients are assumed to be with respect to the primitive variables + u_boundary = boundary_condition.boundary_value_function(x, t, equations) + + return cons2prim(u_boundary, equations) +end + +@inline function (boundary_condition::BoundaryConditionDirichlet)(flux_inner, + u_inner, + normal::AbstractVector, + x, t, + operator_type::Divergence, + equations::CompressibleNavierStokesDiffusion2D{ + GradientVariablesPrimitive + }) + # for Dirichlet boundary conditions, we do not impose any conditions on the viscous fluxes + return flux_inner +end end # @muladd diff --git a/test/test_parabolic_2d.jl b/test/test_parabolic_2d.jl index 3fff4382cd1..967aa1069a0 100644 --- a/test/test_parabolic_2d.jl +++ b/test/test_parabolic_2d.jl @@ -289,6 +289,14 @@ isdir(outdir) && rm(outdir, recursive=true) ) end + @trixi_testset "P4estMesh2D: elixir_navierstokes_convergence_nonperiodic.jl" begin + @test_trixi_include(joinpath(examples_dir(), "p4est_2d_dgsem", "elixir_navierstokes_convergence_nonperiodic.jl"), + initial_refinement_level = 1, tspan=(0.0, 0.2), + l2 = [0.00040364962558511795, 0.0005869762481506936, 0.00091488537427274, 0.0011984191566376762], + linf = [0.0024993634941723464, 0.009487866203944725, 0.004505829506628117, 0.011634902776245681] + ) + end + @trixi_testset "P4estMesh2D: elixir_navierstokes_lid_driven_cavity.jl" begin @test_trixi_include(joinpath(examples_dir(), "p4est_2d_dgsem", "elixir_navierstokes_lid_driven_cavity.jl"), initial_refinement_level = 2, tspan=(0.0, 0.5),